What is Involved in an Engine Swap?

I currently have never done such a thing nor seen it done but I feel like I understand just enough to where you give me two cars and it's a straightforward swap, and I could do it (just give me a month). I thought I would give you a glimpse into how my amateur mechanic mind works. I'll come back in a year and see how much I've learned. My goal is to rebuild a small motor if I can get my hands on one cheap within a year from now. (2JZ?)

Man those Turbobricks with LS motors, you gotta love them! 

The hardest thing for me would be the wiring harness. Although truly, you should be getting a kit with a conversion wire harness too so you can hook it up to the new car. It should have directions or at the very least, diagrams to help you hook everything up. To me, this would be the true test. I do believe that eventually, everything would be plugged in the right place. Electrical diagrams aren't super hard to read. You just have to understand what the symbols mean. I know, however, that they get harder to read the more tired you get. Maybe take a break if you're having problems.

Take a nap to refresh your mind and come back to it. You will make less errors.

If I was swapping out the same engine, like taking out a blown 1UZFE and putting a good 1UZFE back in, the job would be much, much easier. The way I would do it if I was getting the motor myself is to keep everything plugged in and cut the wires sticking out. This way, I could simply compare the connectors and get 90% of the engine hooked up just like that. Don't cut your wires when taking out your old engine unless the job requires it for a swap. You want to keep all of your original electrical connectors on your car.

So again - if you're taking an engine from a donor car, leave the wires connected and cut them to leave them attached to the motor. Taking out your own engine, disconnect the wires normally.

There is a number of things that go into a swap. Some motors and cars, you can just forget it. You need to find a similar-enough car to fit your motor. Although LS1 swaps have been done on probably every brand of car, typically similar brands' motors are easiest to swap.

For example, a Toyota Camry V6 motor into a first gen Toyota MR2. They're both Toyotas. Except the MR2 has, what, 130 bhp? The V6 has about 200 bhp and a market for mods. This is a pretty straightforward swap except for one issue. There is very little room. You have to wiggle the tranny and the engine into the MR2 as one unit, I believe. That setup there leaves you with practically no more room in the engine bay. Remember, they could only fit a 4-banger initially.

You can always cut holes for turbos.

That's a Porsche 944 with an LS2, I believe. 

You're going to need new engine mounts (probably machined custom unless they make them for the swap you're doing), probably headers, exhaust. And you need a transmission that will not only bolt onto the motor but the driveshaft. Sometimes it's best to get a car with a strong transmission and put the motor in it. The more horsepower you have also, the stronger the tranny has to be.

You can adapt some trannies to some motors but everything is individual. Don't forget that nowadays they have adapters that allow you to mate engines with trannies that wouldn't have been possible 20 years ago.

Keep in mind that I'm talking about a swap. Putting one car's motor into a different car. I just want to mention this because, as I said earlier, changing out the same engine is much easier.

Now let me just say something. I would do this if I had a place to do it, no questions asked. Why? Because when it comes to building cars, it doesn't really get any sweeter than a good engine swap. And doing one connects all the bits of knowledge in your head creating a concrete system to go by.

Mmm, diagrams. Learn to love them.

And if you are up to the task and can actually pull it off, you must know a great deal about every system on that damn car. This puts you in the position to build the car you really want. At that point, roads open for you so let's leave it at that. Doing this as an amateur will skyrocket your skills, as I said.

If you're young and maybe you want to be a mechanic, then do it but always keep a vision for yourself for the future and follow it. Does your future include a lot of pain? Maybe there's something drastic that you need to change. I was told this in my early 20s and it went in one ear and out the other. Someone told me to use my trade to start a business. At the time, I thought that wasn't for me but years later I'm doing exactly that.

Ofcourse hindsight is 20/20 but when I had the opportunity to do it when I was younger, I should have. Instead I was partying and getting wasted. It was fun at the time but ehh... I wouldn't say it was worth it.

That's a 1UZFE in a something. All I know is it looks amazing. 

Swapping Same Motor
Since we're talking about taking out engines, here's a very basic rundown of swapping out the same motor and what you need to do. This may help you get a better idea of how to do a swap. The info goes hand in hand.

You need to isolate the engine. This requires you to unplug every electrical connector, hose, fuel lines, transmission (remove the bolts), and other stuff. Take a picture of how the motor looks before you take it apart. Take a few pictures from different angles. It's a very useful trick to help you remember where everything goes later.

Before you do that, you should drain all of your fluids. That's an annoying part of this. Nonetheless, you have to get all of the liquid out of the engine before you hoist it out.

Once everything is disconnected including the transmission, the last thing is the engine mounts. Don't take those off until you set up something under the engine to hold it up! It should also be connected to the chain at this point.

Go ahead and undo the bolts for the engine mounts and pull the engine out and up. You might notice a wire or two you missed. Go slow and have a partner watching if you can. Set the old engine down somewhere.

Now is when you want to clean your engine bay. It won't be this empty again for a long time if ever. When you're ready, position the new engine and lower it into place. Then push it onto the transmission, get it supported with something, and it should also be lined up with the engine mounts. Put the nuts and bolts back on and your new engine is ready to be hooked up! Some people will put both the tranny and engine in at the same time. Just depends on what you're trying to do.

Sounds pretty easy, doesn't it? It's really not that hard if you know about cars and have even just decent knowledge of how all of the systems work together. No, it's not "easy" but yes, you can do it. It's really a matter of knowledge that you can gather over time very easily. Today we have the internet packed with tutorials and we also have books. Shop manuals are the best tool. If you can get one for your car, do it. The problem is that they run about $3-400.

Keep turning those wrenches, people. I have much love for everybody. Come back every couple of days for a new article.

- Rokas Kirvelis